Two known types of stalk-like crops in the North American market are sugarcane and sorghum. Other stalk-like or cane-like crops have been receiving increasing attention in bioenergy circles, such as miscanthus, energy cane, and giant reed. During the harvesting of sugarcane, it is known to top the sugarcane plant by cutting off the top portion of the plant using a separate cutter head and allowing the top of the plant to simply fall to the ground.
Sorghum is a major cereal grain that is one of the oldest known crops and is used as a staple food in many parts of Africa and Asia. Sorghum is a major feed grain crop in the US, Mexico, Argentina, Australia, and South Africa. It is believed that sorghum was introduced into the United States in the 1700's and some believe that Benjamin Franklin introduced the first grain sorghum crop. The seed of grain sorghum is the smallest of the major spring-planted field crops, such as corn and soybeans.
Both sugarcane and sorghum are members of the grass family. Sugarcane is native to warm, temperate to tropical regions, the cane having stout, jointed, fibrous stalks that are rich in sugar and measure six to nineteen feet tall. Sugarcane is able to convert up to two percent of the incident solar energy into biomass. Once sugarcane is planted, a stand can be harvested several times. After each harvest, the cane sends up new stalks called rattons. Each successive harvest produces a decreasing yield, eventually leading to a replanting operation.
The harvesting of sugarcane includes the cutting of the cane at the base of the stalk, stripping the leaves, chopping the cane into consistent lengths, and depositing the cane into a transporting device. The harvester typically blows the leaves and such back onto the ground.
Sugarcane harvesting machines utilize a basecutter device that is integral with the main frame of the machine. The height of the cut is regulated by the raising and lowering of the main portion of the machine attached to a mainframe. The adjustment of the cutting height also caused the adjustment in the height of the rest of the machine, including the operator's cab, which can cause discomfort to the operator as the harvester, along with the operator, is moved up and down by frequent adjustments in cutting height. This is particularly a problem on machines that use some sort of automatic basecutter height adjustment.
A device by Copersucar of Brazil was tried several years ago that separated the basecutter box from the main frame of the harvester. The intent of this was to make the basecutter float. The basecutter was mounted on pivoting arms that had a spring, allowing the movement of the basecutter. The bottom of the cutting disk had a bell-shape for riding on the ground in an attempt to regulate cutting height.
What is needed in the art is an improved and efficient height adjustment for the basecutter of a stalk plant harvester.